@Background Pony #5478  
Hence, “in a word” and a link to some more info. :P
 
The main point being that, contrary to popular belief, chlorine + ammonia doesn’t actually produce mustard gas.

@Exhumed Legume  
Chloramines are one product.
 
Recall that sodium hypochlorite, or, rather, the substance they give that label (I seem to recall that no hypochlorite salt has been isolated outside of solution, and the hypochlorite ion’s suspected existence is only one of several models) is just chlorine gas dissolved in an aqueous solution of sodium hydroxide. Adding ammonia to the system causes the chlorine gas to jump out of solution rapidly. This is evidence for some models of a hypochlorite ion which briefly latch onto the unpaired sp3 orbitals sticking out of the nitrogen atom then break loose again with the chlorine freed.
 
Chloramine is a nasty, toxic substance, but chlorine gas in sufficient concentrations is more than capable of doing a person grievous, even lethal harm all by itself. See also, Ypres and the Somme.

@LeAlbinoPony  
False; ammonia and bleach contain neither carbon nor sulfur, both of which are components of sulfur mustard.
 
The correct answer is, in a word… chloramines.

@Background Pony #AA1D  

 
Two words: Mustard gas.

Now to mix dem ammonia and bleach together! What cold possibly go wrong?!

Five minutes later:
 

… :C